Have a look on the following site:
https://www.sensorcom.com/product.asp?P_ID=956&PT_ID=280
https://s164.photobucket.com/albums/u13/bertowi/?action=view¤t=microbuds.jpg&slideshow=true&interval=3
I ordered a pair of these earphones from the UK. They work excelled. It is the ones the F1...